A 50-year-old lady was admitted with heart failure. Her echocardiogram showed reduced ejection fraction of 35%. She was given intravenous furosemide and improved. On discharge, she was started on guideline- directed medical therapy for heart failure. She was started on empagliflozin, lisinopril and spironolactone. 

(a) Name the FOUR classes of drugs that are used as part of guideline- directed medical therapy of heart failure. (4 marks) 

(b) What is the mechanism of action of lisinopril? How is it helpful in the treatment of heart failure? (3 marks) 

(c) Name TWO side effects of spironolactone. (2 marks) 

(d) What is the mechanism of action of empagliflozin? What are the potential adverse effects of empagliflozin? What precautions should be taken during acute illness? (5 marks) 

(e) Name THREE beta blockers with long term benefits in heart failure. (3 marks) 

(f) Despite optimal treatment, the patient was readmitted with acute heart failure three months later. Her physician considers starting her on an angiotensin receptor-neprilysin inhibitor ("ARNi"). What are the adverse effects of ARNI? Which of her current medications needs to be discontinued? (3 marks)